If you want WiFi 24/7, get a Verizon 4G LTE jetpack or they also have other types, you can buy these things under a 2 year contract which you need to be 18 or have your parents get it and can cost 30-40 a month with 2gbs of data a month. They also sell them under no contracts but the devices will be older models but brand new which is nothing to complain about. They will get you 3gb of data on cards you can get from places such as bestbuy and maybe even verizon stores, they have other brands out there but I am a verizon user so I don't trust really any other carriers especially sprint. But, that's the most I can recommend, best of luck otherwise get an iPhone, unlock it and get on T-Mobile's network, that is legal last time I checked.
What a Verizon 4G LTE jetpack under 2 year contract looks like.
